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Using two strains of Salmonella enteritidis, one susceptible and one resistant to ampicillin, we studied the efficacies of ampicillin, gentamicin, ampicillin plus gentamicin, ofloxacin, and cefotaxime for the treatment of experimental salmonella endocarditis. Rabbits were treated for 3 days with dosages of antibiotic selected to achieve concentrations in serum equivalent to those obtained in humans during therapy. Aortic salmonella endocarditis seemed to be very difficult to treat, and all antimicrobial regimens failed to achieve the complete sterilization of cardiac vegetations. In vitro studies did not accurately predict the in vivo response to therapy, and no correlations regarding the synergistic activity of the combination of ampicillin plus gentamicin were observed. For the ampicillin-susceptible S. enteritidis isolate, ampicillin and cefotaxime produced the greatest reduction in the number of organisms in vegetations, with no significant differences between them. For the ampicillin-resistant strain, the combination of ampicillin with gentamicin produced a synergistic effect that was not anticipated by the in vitro studies. Both cefotaxime and ofloxacin were effective in reducing the number of microorganisms in the vegetations, although the reduction produced by cefotaxime was less that that produced against the ampicillin-susceptible strain. Monotherapy with gentamicin exhibited only modest activity against the ampicillin-susceptible S. enteritidis strain.

Using two strains of Staphylococcus aureus, one susceptible and one heterogeneously resistant to methicillin, for which MICs and MBCs of trimethoprim-sulfamethoxazole (TMP-SMX) were 0.06 and 0.06 micrograms/ml and 0.06 and 0.25 microgram/ml, respectively (concentrations are those of TMP), we studied the efficacies of TMP-SMX and cloxacillin, teicoplanin, and vancomycin for treatment of experimental staphylococcal endocarditis. Rabbits were treated with dosages of TMP-SMX selected to achieve concentrations in serum equivalent to that obtained in humans treated for Pneumocystis carinii pneumonia. The overall mortality rate of rabbits treated with TMP-SMX was 84% at day 3, not different from that of the control groups (P > 0.1). No sterile vegetations were observed to be present in control groups or in animals treated with TMP-SMX. However, 26, 60, and 75% of rabbits treated with teicoplanin, cloxacillin, and vancomycin, respectively, showed sterile vegetations. For methicillin-susceptible S. aureus (MSSA), the mean vegetation counts were not significantly different between the control group and the group treated with TMP-SMX (P > 0.1). For methicillin-resistant S. aureus (MRSA), treatment with TMP-SMX was more effective than no therapy, decreasing the number of organisms in vegetations (P < 0.01). For both strains, therapy with cloxacillin and therapy with teicoplanin or vancomycin were significantly more effective than therapy with TMP-SMX. Despite high concentrations of teicoplanin in serum which exceeded MBCs for staphylococci more than 50 times at the peak and 10 times at the trough, therapy with cloxacillin or vancomycin was superior to therapy with teicoplanin against both MSSA and MRSA. These data do not support the use of TMP-SMX in treatment of endocarditis and other severe staphylococcal infections with high bacterial counts.

Intraventricular teicoplanin 10–15 mg was administered daily to three patients with cerebrospinal fluid (CSF) shunt infections due toStaphylococcus epidermidis andEnterococcus faecalis. Teicoplanin concentrations in CSF 24 h after intrathecal injection of the drug exceeded four- to eight-fold the MICs for the infecting microorganisms. CSF cultures rapidly became negative and shunt devices were withdrawn and replaced in the same operative procedure. Intraventricular teicoplanin was well tolerated. No relapses occurred. Teicoplanin may be an alternative to vancomycin for the antimicrobial therapy of CSF shunt infections.

Histoplasmosis is an endemic mycosis of the Americas, Africa, and Asia. In Spain, it is the most common imported endemic mycosis appearing in the literature, and its incidence is on the rise. Proper differential diagnosis of the disease must be taken into consideration by otorhinolaryngologists, as the clinical manifestations of histoplasmosis may simulate more prevalent diseases such as cancer or tuberculosis. We present the case of a Spanish patient with focal involvement of the larynx and offer a review of the relevant literature.